A novel three-dimensional printed guiding device for electrode implantation of sacral neuromodulation

Application of Augmented Reality for Accurate Punctures During Stage 1 Sacral Neuromodulation

PURPOSE

Precise electrode placement is crucial for the success of sacral neuromodulation (SNM). The aim of this study was to explore a more accurate and convenient method for positioning punctures during the first stage of SNM.

METHODS

This retrospective study compared preoperative baseline values, intraoperative indicators, postoperative scores, and other clinical data from 130 patients who underwent SNM electrode implantation at our department between 2018 and 2023. The patients were divided into an experimental group and a control group to assess the advantages and feasibility of augmented reality (AR)-guided sacral nerve electrode implantation.

RESULTS

The experimental group experienced fewer intraoperative puncture attempts and achieved more accurate AR-guided localization punctures. Additionally, there were more responsive electrode contact points (2.74±0.51 vs. 2.46±0.74) and a lower initial voltage postimplantation (1.09±0.39 V vs. 1.69±0.43 V). The number of intraoperative x-ray fluoroscopies was significantly lower in the experimental group than in the control group (5.94±1.46 vs. 9.22±1.93), leading to a shorter overall operation time (61.32±11.27 minutes vs. 83.49±15.84 minutes). Furthermore, there was no need for additional local anesthetic drugs during the surgery in the experimental group. Comparative observations revealed no significant differences in intraoperative blood loss or the sacral hole location for electrode implantation between the 2 groups. Although the incidence of wound infection and the rate of permanent implantation in stage 2 were similar in both groups, the pain score on the first day postoperation was significantly lower in the experimental group than in the control group (2.62±0.697 vs. 2.83±0.816).

CONCLUSION

AR-guided sacral nerve modulation implantation can reduce both the number of punctures and the duration of the operation while ensuring safety and effectiveness. This technique can enhance the contact points of the response electrode, effectively lower the initial response voltage, and stabilize the electrode.

Clinical applications of 3D printing in colorectal surgery: A systematic review

BACKGROUND

The utilization of three-dimensional printing has grown rapidly within the field of surgery over recent years. Within the subspecialty of colorectal surgery, the technology has been used to create personalized anatomical models for preoperative planning, models for surgical training, and occasionally customized implantable devices and surgical instruments. We aim to provide a systematic review of the current literature discussing clinical applications of three-dimensional printing in colorectal surgery.

METHODS

Full-text studies published in English which described the application of 3D printing in pre-surgical planning, advanced surgical planning, and patient education within the field of colorectal surgery were included. Exclusion criteria were duplicate articles, review papers, studies exclusively dealing with surgical training and/or education, studies which used only virtual models, and studies which described colorectal cancer only as it pertained to other organs.

RESULTS

Eighteen studies were included in this review. There were two randomized controlled trials, one retrospective outcomes study, five case reports/series, one animal model, and nine technical notes/feasibility studies. There were three studies on advanced surgical planning/device manufacturing, six on pre-surgical planning, two on pelvic anatomy modeling, eight on various types of anatomy modeling, and one on patient education.

CONCLUSIONS

While more studies with a higher level of evidence are needed, the findings of this review suggest many promising applications of three-dimensional printing within the field of colorectal surgery with the potential to improve patient outcomes and experiences.

Evaluation of optical tracking and augmented reality for needle navigation in sacral nerve stimulation

BACKGROUND AND OBJECTIVE

Sacral nerve stimulation (SNS) is a minimally invasive procedure where an electrode lead is implanted through the sacral foramina to stimulate the nerve modulating colonic and urinary functions. One of the most crucial steps in SNS procedures is the placement of the tined lead close to the sacral nerve. However, needle insertion is very challenging for surgeons. Several x-ray projections are required to interpret the needle position correctly. In many cases, multiple punctures are needed, causing an increase in surgical time and patient's discomfort and pain. In this work we propose and evaluate two different navigation systems to guide electrode placement in SNS surgeries designed to reduce surgical time, minimize patient discomfort and improve surgical outcomes.

METHODS

We developed, for the first alternative, an open-source navigation software to guide electrode placement by real-time needle tracking with an optical tracking system (OTS). In the second method, we present a smartphone-based AR application that displays virtual guidance elements directly on the affected area, using a 3D printed reference marker placed on the patient. This guidance facilitates needle insertion with a predefined trajectory. Both techniques were evaluated to determine which one obtained better results than the current surgical procedure. To compare the proposals with the clinical method, we developed an x-ray software tool that calculates a digitally reconstructed radiograph, simulating the fluoroscopy acquisitions during the procedure. Twelve physicians (inexperienced and experienced users) performed needle insertions through several specific targets to evaluate the alternative SNS guidance methods on a realistic patient-based phantom.

RESULTS

With each navigation solution, we observed that users took less average time to complete each insertion (36.83 s and 44.43 s for the OTS and AR methods, respectively) and needed fewer average punctures to reach the target (1.23 and 1.96 for the OTS and AR methods respectively) than following the standard clinical method (189.28 s and 3.65 punctures).

CONCLUSIONS

To conclude, we have shown two navigation alternatives that could improve surgical outcome by significantly reducing needle insertions, surgical time and patient's pain in SNS procedures. We believe that these solutions are feasible to train surgeons and even replace current SNS clinical procedures.

Three-Dimensional Printing of Medical Devices Used Directly to Treat Patients: A Systematic Review

Until recently, three-dimensional (3D) printing/additive manufacturing has not been used extensively to create medical devices intended for actual clinical use, primarily on patient safety and regulatory grounds. However, in recent years there have been advances in materials, printers, and experience, leading to increased clinical use. The aim of this study was to perform a structured systematic review of 3D-printed medical devices used directly in patient treatment. A search of 13 databases was performed to identify studies of 3D-printed medical devices, detailing fabrication technology and materials employed, clinical application, and clinical outcome. One hundred and ten papers describing one hundred and forty medical devices were identified and analyzed. A considerable increase was identified in the use of 3D printing to produce medical devices directly for clinical use in the past 3 years. This is dominated by printing of patient-specific implants and surgical guides for use in orthopedics and orthopedic oncology, but there is a trend of increased use across other clinical specialties. The prevailing material/3D-printing technology used were titanium alloy/electron beam melting for implants, and polyamide/selective laser sintering or polylactic acid/fused deposition modeling for surgical guides and instruments. A detailed analysis across medical applications by technology and materials is provided, as well as a commentary regarding regulatory aspects. In general, there is growing familiarity with, and acceptance of, 3D printing in clinical use.

[Comprehensive review of 3D printing use in medicine: Comparison with practical applications in urology]

INTRODUCTION

Over the past few years, 3D printing has evolved rapidly. This has resulted in an increasing number of scientific publications reporting on the medical use of 3D printing. These applications can range from patient information, preoperative planning, education, or 3D printing of patient-specific surgical implants. The objective of this review was to give an overview of the different applications in urology and other disciplines based on a selection of publications.

METHODS

In the current narrative review the Medline database was searched to identify all the related reports discussing the use of 3D printing in the medical field and more specifically in Urology. 3D printing applications were categorized so they could be searched more thoroughly within the Medline database.

RESULTS

Three-dimensional printing can help improve pre-operative patient information, anatomy and medical trainee education. The 3D printed models may assist the surgeon in preoperative planning or become patient-specific surgical simulation models. In urology, kidney cancer surgery is the most concerned by 3D printing-related publications, for preoperative planning, but also for surgical simulation and surgical training.

CONCLUSION

3D printing has already proven useful in many medical applications, including urology, for patient information, education, pre-operative planning and surgical simulation. All areas of urology are involved and represented in the literature. Larger randomized controlled studies will certainly allow 3D printing to benefit patients in routine clinical practice.

A Three-Dimensional Print Model of the Pterygopalatine Fossa Significantly Enhances the Learning Experience

The pterygopalatine fossa (PPF) is a bilateral space deep within the skull that serves as a major neurovascular junction. However, its small volume and poor accessibility make it a difficult space to comprehend using two-dimensional illustrations and cadaveric dissections. A three-dimensional (3D) printed model of the PPF was developed as a visual and kinesthetic learning tool for completely visualizing the fossa, its boundaries, its communicating channels, and its neurovascular structures. The model was evaluated by analyzing student performance on pre- and post-quizzes and a student satisfaction survey based on the five-point Likert scale. The first cohort comprised of 88 students who had never before studied the PPF. The second cohort consisted of 30 students who were previously taught the PPF. Each cohort was randomly divided into a control group who were provided with a half skull and an intervention group that were provided with the 3D printed model. The intervention group performed significantly better on the post-quiz as compared to the control group in cohort I (P = 0.001); while not significant, it also improved learning in cohort II students (P = 0.124). Satisfaction surveys indicated that the intervention group found the 3D printed model to be significantly more useful (P < 0.05) as compared to the half skull used by the control group. Importantly, the effect sizes for cohorts I and II (0.504 and 0.581, respectively) validated the statistical results. Together, this study highlights the importance of 3D printed models as teaching tools in anatomy education.

Current applications of three-dimensional printing in urology

Three-dimensional (3D) printing or additive manufacturing is a new technology that has seen rapid development in recent years with decreasing costs. 3D printing allows the creation of customised, finely detailed constructs. Technological improvements, increased printer availability, decreasing costs, improved cell culture techniques, and biomaterials have enabled complex, novel and individualised medical treatments to be developed. Although the long-term goal of printing biocompatible organs has not yet been achieved, major advances have been made utilising 3D printing in biomedical engineering. In this literature review, we discuss the role of 3D printing in relation to urological surgery. We highlight the common printing methods employed and show examples of clinical urological uses. Currently, 3D printing can be used in urology for education of trainees and patients, surgical planning, creation of urological equipment, and bioprinting. In this review, we summarise the current applications of 3D-printing technology in these areas of urology.

Systematic review of the applications of three-dimensional printing in colorectal surgery

AIM

Three-dimensional (3D) printing has been recognized as a revolutionary technological innovation that has benefitted numerous disciplines, including medicine. The present systematic review aimed to demonstrate the current applications of 3D printing in colorectal surgery along with the limitations and potential future applications of this innovation.

METHOD

A PRISMA-compliant systematic literature search of studies that applied 3D printing in colorectal surgery in the period from January 1990 to July 2018 was conducted. Electronic databases including PubMed/Medline, Scopus and the Cochrane Library were searched. All full-text original articles were eligible for inclusion.

RESULTS

Nine studies including 58 patients with a median age of 60.7 years were reviewed. The studies assessed 3D printing in patients with planned stoma construction, colon cancer with liver metastasis, right colon cancer, rectal cancer, intractable constipation and anal fistula. The applications of 3D printing were classified into three categories: patient education, preoperative planning and evaluation of response of colorectal liver metastasis to chemotherapy. 3D printed models aided in planning resection of colorectal liver metastasis, facilitating D3 lymphadenectomy in complete mesocolic excision, improving the understanding of pelvic anatomy in laparoscopic rectal cancer treatment, guiding electrode implantation in sacral neuromodulation for intractable constipation, and elucidating the morphology of anal fistula tract and anal sphincter muscles.

CONCLUSION

Colorectal surgery may benefit from 3D printing in enhancing patient education before stoma construction, preoperative planning and evaluation of the response of liver metastasis to chemotherapy using 3D ultrasonography.

Application of an individualized and reassemblable 3D printing navigation template for accurate puncture during sacral neuromodulation

OBJECTIVE

To evaluate the feasibility and safety of an individualized and reassemblable three-dimensional (3D) printing navigation template for making accurate punctures during sacral neuromodulation (SNM).

METHODS

From July 2016 to July 2017, 24 patients undergoing SNM were enrolled. Conventional X-ray guidance was used in the control group, which included 14 patients, while the 3D printing template was used in the experimental group, which included 10 patients. The number of punctures, the average puncture time, the exposure to X-ray, the adjustment time during the operation and the testing of the SNM device, the infection and haemorrhage rate, and the implantable pulse generator (IPG) implantation rates were compared between the two groups.

RESULTS

In total, 24 patients successfully underwent stage I. When comparing the control group and the experimental group, the number of punctures were 9.6 ± 7.7 and 1.5 ± 0.7, respectively; the average puncture times were 35.4 ± 14.6 and 4.1 ± 2.2 min, respectively; and the X-ray exposure levels were 8.37 ± 4.83 mAs and 2.34 ± 0.54 mAs, respectively. No postoperative complications were reported in either group. The IPG implantation rates were not different between the two groups.

CONCLUSION

The 3D printing template for SNM can help us to perform accurate and quick punctures into the target sacral foramina, reduce X-ray exposure, and shorten the operation time. For patients with obesity, sacral variation, sacral bone fractures or losses and for patients who are unable to tolerate the prone position during operation, use of the 3D printing template is recommended.